Thirty two people have died in police custody since 1992, with all but one of the fatalities being men.
In figures released under the Official Information Act, three people died in police custody in 2015 - the first year to record deaths in custody since 2008 when two people died.
The year with the most deaths in custody was 1996 when five people died.
Four more died in 1997, but since the turn of the century deaths in police custody have become increasingly rare.
Just one person died in police custody during the years 2000, 2001 and 2004, while two died in 2005 and three in 2003.